PEST BIOLOGY, ECOLOGY, AND INTEGRATED PEST MANAGEMENT FOR SUSTAINABLE AGRICULTURE
Location: North Central Agricultural Research Laboratory
Title: Reproductive ecology of predaceous Heteroptera
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 8, 2011
Publication Date: October 18, 2011
Citation: Lundgren, J.G. 2011. Reproductive ecology of predaceous Heteroptera. Biological Control. 59:37-52.
Interpretive Summary: Biological control of insect pests is contingent in the predators being in the right place at the right time. Synchrony of natural enemies with pests is largely dependent on when and where a predatory bug reproduces. Predatory bugs (Hemiptera: Reduviidae, Pentatomidae, Anthocoridae, Nabidae, and Geocoridae) are important biological control agents in cropland, and this paper reviews the literature on how, when, and where these economically important insect reproduce. The discussion begins by describing the physiological basis for reproduction in female predatory bugs, and the structure of their eggs. These two factors restrict how fast a bug population can increase and when and where the eggs will survive. But the rate of population increase is influenced by a range of parameters, categorized here as 1) physiological status of the mother (mating status, size, nutritional status), 2) environmental factors (temperature, photoperiod, water availability), and 3) the influence of natural enemies of these beneficial insects (pathogens, parasitoids, predators, etc). The behavior of egg-laying is then described in detail for species that insert their eggs into plant tissues, and those that lay their eggs in clutches on plants or debris (the two main strategies in this group). The physiology and behavior of reproduction forms the basis for 1) improved mass rearing of these biological control agents, 2) conservation of beneficial species in and around cropland, and 3) increasing predation on key crop pests.
Reproductive ecology entails relating the physiology and behavior of an organism to its environment and the community in which it lives. Terrestrial predatory Heteroptera (including Anthocoridae, Geocoridae, Miridae, Nabidae, Pentatomidae, Phymatidae, and Reduviidae) display a wide range of reproductive ecologies. But in spite of this variability, a review of the literature reveals certain underlying trends that are useful in understanding how generalist predators function within their environments. First, the reproductive ecology of predatory bugs is inherently coupled to the physiology of the female and her eggs. Second, three population parameters directly tied to reproduction (maturation rates, realized fecundity, and reproductive diapause) have great bearing on the rate of population increase and reproductive success of a predatory bug, but these three parameters fluctuate widely within and among species. The variables that affect these processes include the physiological status of the mother (mating status, age and size, and nutritional status), the abiotic environment in which she and her eggs live (temperature, photoperiod, water availability), and natural enemies that attack eggs and reproductive females. A final trend observed in the literature involves the hierarchy of events that must occur before a female finds a suitable oviposition site. Females all must locate preferred habitats, plants/substrates, and microsites in which to insert or deposit an egg, but they use a variety of tactics and cues in order to accomplish this, depending on their life history traits. Examining the factors that constrain and promote the reproductive potential of predatory Heteroptera will make biological control programs that center on them more reliable and sustainable.